The present invention relates to methods and systems for real time call tracing. More particularly, the present invention relates to database driven methods and systems for real time call tracing.
In order to diagnosis problems, detect fraud, and perform security screening in telecommunications networks, it is often necessary to capture, in real time, signaling messages used to establish, maintain, and tear down calls. The capturing of signaling messages relating to a call in real time is referred in the telecommunications industry as real time call tracing. Real time call tracing can be difficult because the signaling links that carry signaling messages may operate at different speeds and signaling messages relating to the same call may be sent over different links.
Conventional real time call tracing systems utilize signaling link probes to copy and buffer messages from signaling links. For example, U.S. patent application Publication No. US 2002/0071530 (hereinafter, xe2x80x9cthe ""530 Publicationxe2x80x9d) discloses a real time call tracing system that uses link probes copy messages from signaling links. Each link probe includes a probe buffer. Messages received from a signaling link are stored in the probe buffer. Trigger criteria are applied to the signaling messages stored in each probe buffer. If a signaling message stored in a probe buffer matches a trigger condition, the message is sent to an element manager associated with the probe that discovered the signaling message. The element manager formulates and sends a new trigger condition to each of the signaling link probes. Each of the signaling link probes analyzes messages in its probe buffer based on the new trigger criteria.
One problem with conventional real time call trace systems, such as that described in the ""530 Publication, is that the memory and processing capacity of signaling link probe devices is limited. Because of the limited storage capacity at conventional signaling link probes, many conventional real time call trace systems utilize circular buffers at signaling link probes. Using circular buffers at signaling link probes allows data to be continuously written to a signaling link probe buffer. However, if data at the beginning of the buffer is not read before the buffer becomes full, the data will be overwritten with new data, and the signaling messages needed to perform a real time call trace may be lost.
Another problem with probe-buffer-based call tracing systems, such as that described in the ""530 Publication, is that the systems do not truly operate in real time. For example, analyzing messages stored in a buffer means that the messages have already been received and are not being analyzed in real time as they arrive. Moreover, if a message is not found in the historical data stored in a buffer, the call trace may fail.
Yet another problem associated with conventional probe-buffer-based call tracing systems is that signaling link probe buffers may utilize volatile memory for storing received signaling messages. Storing these signaling messages in volatile memory will result in loss of data if a signaling link probe loses power.
Yet another problem associated with conventional probe-buffer-based call tracing systems is that link probes typically consist of dedicated message copying hardware with proprietary interfaces on the message analysis side. Using dedicated hardware with proprietary interfaces limits the ability to write real time call trace applications that interface with the hardware and have access to the messages stored in the signaling link buffers.
Accordingly, in light of these difficulties associated with conventional real time call tracing systems, there exists a need for improved methods and systems for real time call tracing.
The present invention includes improved methods and systems that use a database rather than link probe buffers for real time call tracing. In one exemplary implementation, the real time call tracing system is completely probeless. Messages are copied directly from signaling link interface cards in a signaling message routing node, such as a signal transfer point. The copied messages are sent to a network monitoring processor associated with the signal transfer point. The network monitoring processor stores the messages in a relational database. A network monitoring server located remotely from the network monitoring processor sends a request to the network monitoring processor for a real time call trace. The network monitoring processor searches the relational database for historical data copied from the signaling link for the message. If the message is not located in the historical data, the network monitoring processor analyzes messages in real-time as the message are received.
Utilizing a database, rather than link probe buffers, greatly increases the scalability, reliability, and flexibility of a real time call tracing system. For example, the database may be stored in memory on a general-purpose computing platform separate from signaling link probe hardware. Because the database can be located on any suitable general-purpose computing platform, the number of messages that can be buffered for real time call tracing purposes is scalable based on hard disk size. The reliability of the system is also increased because the database is stored in nonvolatile memory located on one or more system disks. The flexibility of the system is increased because the database can be located on any suitable network element at any suitable location in the network.
Accordingly, it is an object of the present invention to provide improved methods and systems for real time call tracing that utilize a database rather than link probe buffers for real time call tracing.
It is another object of the invention to provide a method for real time call tracing that combines the analysis of historical data stored in the database with data received in real time.
Some of the objects of the invention having been stated hereinabove, and which are addressed in whole or in part by the present invention, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.